THE CHANGING WAN MATCHING THE WAN TO BUSINESS NEEDS. James Walker, Vice President Managed Network Services WAN Summit 7th October 2015

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1 THE CHANGING WAN MATCHING THE WAN TO BUSINESS NEEDS James Walker, Vice President Managed Network Services WAN Summit 7th October 2015 tatacommunications-newworld.com youtube.com/user/tatacomms 2015 Tata Communications. All Rights Reserved. TATA COMMUNICATIONS and

2 So, what s new? The rise and rise of the cloud Bringing challenges of : Integration with legacy systems Private vs public connectivity Alignment with internal policies, security requirements, regulatory obligations Barriers to entry for smaller cloud providers Increasing use of hybrid VPNs Cost reductions More challenges : Load balancing (MP BGP) Asymmetric routing Cloud connectivity Full dual link utilisation The arrival of early SDWAN services 2

3 Customer requirements Network-centric Application-centric Extensive in-house network expertise Complex traffic engineering requirements Deterministic behaviour High speed core, regional meet-me Private network Limited public cloud, little if any SaaS Tendency to have significant on-premise applications Audit, compliance and security requirements Limited internal network expertise Application performance critical Hybrid networks, mix of private and public traffic Want to increase utilisation levels of the network Increasing use of public cloud and SaaS

4 Network requirements Network-centric Application-centric Deterministic pathing Minimise visibility of customer s routing table Predictable network performance Complex DR scenarios Possible overlay networks Generally high speed (1G+) and growing Challenges around internal cost allocation and logical separation Dynamic bandwidth potentially required Limited sites Service multiplexing TEaaS Managed services Application visibility and reporting Performance optimisation Intelligent load balancing, pathing and use of network resources Integration of multiple services (UC, Internet) Connectivity to public cloud A network that dynamically reacts to application performance and needs Overlay network requirements Typically multi-vendor, multi service

5 HYBRID VPNS AND SDWAN tatacommunications-newworld.com youtube.com/user/tatacomms 2015 Tata Communications. All Rights Reserved. TATA COMMUNICATIONS and

6 Let s start with something very basic No contention in the core SLA guarantees available Premium link Unpredictable with potential contention and jitter Best effort based Cheap and cheerful link

7 A few more scene-setting thoughts Last mile connectivity is the biggest cost in a network Secondary circuit is hardly used (traffic flows less than 1% of the time) Network managers are forced to manage congestion on the primary circuit while the secondary circuit lies idle VPN Backup links fail and no-one notices until they re needed Network management best practice For short term bursts apply QOS techniques and don t increase bandwidth Long term high link utilization buy more bandwidth, burst or offload traffic to alternate path Frequent path change causes harm Always route critical traffic on the best path Primary Circuit Secondary Circuit

8 Now, a little background on SDWAN This is Cisco IWAN but most SDWAN solutions have similar concepts Traffic is hub and spoke Metrics are measured from the hub to the spokes Path selection based on metrics Path abstraction (in IWAN, using DMVPN technology) Hub Master controller automatically pushes policy to spokes Multiple DCs are supported using a concept called a transit site

9 SDWAN still evolving Questions customers should ask their SDWAN provider Do all sites need two connections, or can I have single attached sites? Do all sites have to participate in the overlay? What about IaaS sites? Do I have to migrate everything at once? Can I control spoke to spoke traffic? Can I have different traffic policies at different DCs? û ü û When the primary fails at the DC, does all traffic fail over to the alternate path (for hybrid sites, this is the Internet )? ü What is the impact on router throughput, are older/smaller routers supported? û 70-80% reduction How do I handle local internet breakout at hybrid sites? ü ü Will my load balancing policy cause any issues? ü û? û Asymmetric routing 9

10 Problem statement Metric based approach Path Oscillation Problem Link utilization increases on last mile Premium applications are offloaded again. Congestion reoccurs Metric for critical application (that has the most stringent requirements) drops first Variable internet performance impacts application performance metrics Critical applications are offloaded Offloading causes metrics to improve

11 Final thoughts New applications, cloud and the move to hybrid networking is a very fundamental change Local internet breakout, connections to cloud (eg O365, Skype) and legacy applications are very complex to manage efficiently Managing application prioritisation and failover remains difficult Service providers and the industry are in a state of flux Enterprise customers sit on a spectrum with a spread of requirements which become very different at the two ends SDN and NFV are not yet here and continue to evolve Customers have problems now Overlay providers are an attractive option for frustrated enterprises but can introduce rafts of new issues, and not fix the old ones There is no silver bullet Back to the future? While supporting SDWAN, we are also investing heavily in innovation using legacy protocols Visibility, efficiency, predictability and control are the objectives 11

12 THANK YOU tatacommunications-newworld.com youtube.com/user/tatacomms 2015 Tata Communications. All Rights Reserved. TATA COMMUNICATIONS and